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1.
This work is referred to the characterization of the environmental hydrochemistry in the broader Sapes area – Thrace region, on the basis of physico-chemical properties of surface and groundwaters occurring in the volcanosedimentary formations of this area, where gold mining activities are planned to operate. Volcanic rocks are considerably altered where they are in contact with hydrothermal solutions. Aquifers are formed within these formations. Surface and ground waters are strongly metalliferous and their hydrochemical facies present similar but complex water types. Certain characteristic chemical types are the following: Ca-Mg-HCO3-SO4, Ca-Mg-SO4-HCO3. Ca-SO4, Ca-Mg-SO4. Ca-Na-Cl-HCO3, Na-Cl. A small majority of the water samples present the following order of anion dominance HCO3 ? > SO4 2? > Cl?. Calcium is the dominant cation. Bicarbonates and sulfate ions are the dominant anions. The order of dominance for the heavy metals in surface and ground waters is as follows: Fe > Mn > Zn > Ni > Cu. The saturation index of waters regarding minerals is low. Computer simulation indicates that calcite and dolomite are common minerals in all water samples which are saturated in respect to quartz and argillaceous-siliceous minerals. The most pronounced property of waters is their acidic character. The high metal concentrations are related to water with low pH. Sulfide minerals control the low pH values of waters which is an important control factor for the evolution of the water chemical composition. The abundance of sulfates is attributed to the dissolution of the minerals pyrite (FeS2) and alunite (KAl3(SO4)2(OH)6. The water–mineral interactions are responsible for the chemical composition of waters. Water quality problems can be successfully handled by the use factor analysis. 17 chemical parameters can be substituted by five factors which successfully represent the hydrochemical processes as well as their geographic distribution. Volcanic rocks in the study area have the potential to produce acid drainage.  相似文献   

2.
In spite of increasing numbers of tourists each year, Majorca retains a variety of natural and semi-natural vegetation types. These are principally in the limestone sierra and around the coast. Of the fairly numerous species of endemic plants which occur, some are frequent. The Balearic Islands are also an important staging-post for migrant birds, and the wetlands of Majorca are the most valuable habitat from the ornithological standpoint. This paper summarizes the major vegetation types of Majorca and discusses the contribution made to the conservation value of the island by its 21 species of vascular plants that are recognized as endemic to the Balearic Islands and in 13 cases are exclusively Mallorcan. Finally, the conservation threats arising from urbanization, from indirect effects of development, and from changes in agricultural practice, are briefly discussed.  相似文献   

3.
镉对不同基因型小白菜根系生长特性的影响   总被引：7，自引：1，他引：6  
采用水培试验,研究了镉（Cd）不同处理浓度对两种基因型小白菜（金夏王青梗菜和上海矮抗青）的生长及根系形态的影响。结果表明, 随着Cd 处理浓度的增加,两种基因型小白菜根系除直径无显著差异外,根系鲜重、长度、体积、表面积、根系活力均持续下降,且青梗菜的下降幅度显著高于矮抗青。随着镉处理浓度的增加,两种小白菜体内镉含量明显增加,与处理浓度呈显著正相关。当处理浓度大于Cd2+ 0.25 mg/L,矮抗青地上部与根系镉含量超过青梗菜。两种小白菜地上部分鲜重和光合速率均呈先升后降的趋势,其中青梗菜的临界值为Cd 2+ 0.1 mg/L时,而矮抗青的临界值为Cd2+ 0.25 mg/L时。镉浓度为Cd 2+ 1.0 mg/L时,二品种气孔导度均有显著下降,而蒸腾速率变化相对较小。根系较地上部分对镉更为敏感。两种小白菜对镉浓度的反应虽然总体趋势一致,但青梗菜根系的生物量、形态参数、活力及光合参数的下降幅度显著高于矮抗青,表明矮抗青比青梗菜具有较强的耐镉特性,与种子萌发时的敏感性一致。  相似文献   

4.
锰对板栗实生苗生长及生理效应的影响   总被引：3，自引：1，他引：2  
采用短期培养模拟研究法,在5个Mn2+浓度（0、 0.905、 1.810、 2.715、 3.620 mg/L）处理下,通过测定板栗实生苗木的光合特性、 叶绿素含量、 苗高、 根颚直径、 根系、 生物量与叶片矿质元素等指标,研究了Mn 2+对其生长及生理效应的影响。结果表明, 1）在Mn 2+浓度为0~3.620 mg/L范围内,随Mn2+浓度增大,板栗实生苗净光合速率、 气孔导度、 蒸腾速率、 叶绿素含量、 苗高、 根颚直径、 根重和生物量呈先增加后降低的趋势,其中以Mn 2+浓度1.810和2.715 mg/L处理的效果最好,且两处理间差异不显著（P0.05）; 2）与CK相比,Mn2+增加了苗木对锰的吸收,但抑制了对钙、 铁、 铜的吸收,随Mn2+浓度增大,叶片磷、 硼含量呈先升高后降低趋势,钾含量变化趋势相反; 3）相关分析显示,叶片锰含量与钙、 铁、 铜含量呈显著性负相关（P0.05）,与磷、 钾、 硼含量的相关性均不显著（P0.05）。综上,当Mn2+浓度为1.810和2.715 mg/L时均能显著促进板栗苗木的光合及生长; 但Mn2+浓度不宜过高,大于2.715 mg/L则抑制其生长,不利于矿质元素的均衡吸收。  相似文献   

5.
Analysis of economic data pertinent to the existing municipal wastewater treatment plants (MWTP) in Greece is presented. Thisinformation is important when budgeting for future plants. Thedata include land usage and the costs for construction, operationand maintenance of the form y = ax b, where a and b are calculated coefficients. Equations for cost and landuse were produced for specific systems. Personnel and energy aspects are analysed as they are major contributors to operationalcost. A life cycle analysis (LCA) of plants is undertaken. The results of such an analysis should suggest the most preferabletechnology under given circumstances. Thus, under high energy costs and low level of automation and operation, at low F/M ratios, conventional activated sludge systems are relatively notcost effective. In addition, for cost of land less than US$30 per m2, waste stabilisation ponds are cost effective subjected to minor earthworks.  相似文献   

6.
河北省2006年生态足迹和生态承载力分析   总被引：8，自引：2，他引：6  
利用生态足迹模型对河北省2006年的生态足迹、生产足迹、生态承载力进行了计算和比较.结果表明,2006年河北省人均生态承载力为0.468 3 ghm2,人均生态足迹为2.189 7 ghm2,人均生态赤字为1.721 4 ghm2,人均生产足迹为3.436 3 ghm2,生态足迹强度指数为4.675 8,基于消费的河北省生态足迹多样性为0.837 4,基于生态承载力的河北省生态足迹多样性为0.988 0,基于生态承载力的河北省社会发展指数为0.462 7,基于生产消费的河北省社会发展指数为1.833 8,万元GDP生态足迹为1.290 9 ghm2,河北省的生态贸易赤字为-1.246 6 ghm2,生态耗竭值为2.794 3 ghm2.表明河北省生态经济系统处于生态耗竭、不可持续状态,生态多样性低,生态经济发展能力较差,经济发展属于高能源消费型.河北省只有改革产业结构,转变经济发展方式,建立节能降耗机制,才能实现可持续发展及对自然资源的合理利用.  相似文献   

7.
Radiation ecology of soil animals   总被引：1，自引：0，他引：1  
Summary In this paper the use of animals in organic litter and in the mineral part of soils as bioindicators of ionizing radiation is reviewed. Soil animals are the most suitable biological indicators of radioactive pollution because they are parts of nutritional chains and webs, occur in relatively high numbers and can be collected during most parts of the year. Insects and other forest-dwelling invertebrates are more resistant to radioactive pollution than vertebrates, probably because of the shielding effects of soil constituents. In experiments with 90Sr, 137Cs, 106Ru, 95Zr, 65Zn 125Sb and 239Pu on different components of the mesofauna, earthworms (Oligochaeta) and Myriapoda (Diplopoda and Chilopoda) were affected most intensively, probably because these organisms have an intimate inside and outside contact with soil constituents in the upper layers of the soils. Soil dwellers that are only transitorily in soil or characterized by rapid distribution (predatory Coleoptera, flying insects) are less affected by radiation. Under natural conditions, the doses of irradiation of animals in the upper forest layers are lower than those of dwellers within soil. Forest insects that hibernate in soils at the egg or larval stage are most intensively affected and reduced by radiation. Earthworms prove particularly sensitive to an increased Ra-radiation background. They are among the best bioindicators of polluted soils.In honour of my teacher and colleague Prof. Dr. M.S. Ghilarov  相似文献   

8.
Andosols formed on andesite-basalts, andesite, diabase, and dolerite in the central part of the Adzhar-Trialet Ridge are studied. Their morphological features and some chemical properties are characterized. The soils are diagnosed according to the World Reference Base for Soil Resources (WRB). The soil bulk density, the contents of oxalate-soluble R2O3, adsorbed phosphates, and organic carbon are determined. It is shown that vitric and andic diagnostic features predominate in the investigated soils. According to the adopted classification, these soils are classified as mountain meadow soils. Their morphological features and chemical characteristics correspond to those of Andosols, one of the soil groups in the WRB. It can be expected that these soils are developed in some other regions of volcanic activity in Georgia.  相似文献   

9.
The distributions of free oxides along profiles of some dry rice fields were set forth in the previous reports2,3,4,6), In this paper, the distribution of free oxides in dry rice field5) in polder lands of Kojima-Basin, Okayama pref. is reported. Localities, years elapsed since the planting of rice began in each field and the characteristic of soil profiles are given in Table 1. All the fields are dry rice fields except Soil A, and carry barley or wheat in winter season. Parent materials are similar in all horizons of all soils and rich in fine particles. Fine sands (0.2-0.02 mm) are mainly composed of quartz somewhat accompanied with feldspars, mica, augite and amphibolite. Clays (< 0.002 mm) are mainly composed of halloysite accompanied with a small proportion of montmorillonite. The structure develops well in all the soils.  相似文献   

10.
不同供氮水平对广藿香产量与品质的影响   总被引：2，自引：1，他引：1  
为探讨不同供氮水平对广藿香产量和品质的影响,采用砂培试验,研究了广藿香在3、 6、 12、 18、 24 mmol/L 5种不同氮水平下（用N1、 N2、 N3、 N4、 N5表示）氮营养、 生长性状、 产量、 挥发油含量和品质的变化。结果表明,随着供氮水平的提高,广藿香生长性状参数、 氮营养、 植株鲜（干）重量、 挥发油含量增加,茎和叶的油分含量下降。在广藿香的茎挥发油中,N1和N2处理的12种成分含量均显著高于N4与N5。-广藿香烯、 -愈创木烯、 苦橙油醇、 -愈创木烯、 反式-丁香烯、 广藿香醇、 广藿香酮含量以N1处理最高。刺蕊草烯、 -广藿香烯、 -愈创木烯、 -榄香烯、 异石竹烯含量在N2处理最高。在广藿香叶挥发油所测定的成分中,除了-广藿香烯外, N1和N2 处理的其他成分含量均显著高于N4与N5。-广藿香烯、 -愈创木烯、 -愈创木烯、 -荜澄茄烯、 异石竹烯、 -愈创木烯、 反式-丁香烯、 广藿香醇、 广藿香酮含量在N1处理最高。刺蕊草烯、 -广藿香烯、 -榄香烯含量以N2处理最高。广藿香茎和叶挥发油所测定的12种有效成分N1与N2及N4与N5处理之间无显著差异。总之提高氮水平有利于增加挥发油含量,但油分含量降低。  相似文献   

11.
A prerequisite in any conservation programme of Plant Genetic Resources is estimation of diversity. The inventory of wild and naturalized relatives of priority crops in Venezuela (CWR) is based on the main Catalogues of Flora in the country, selecting taxa closely related to crops, according to the concepts of “gene pool” and “taxonomic group”. We included 47 genera, 217 species and 228 taxa belonging to 28 plant families. Among them, those with higher richness are: Fabaceae, Solanaceae, Araceae, Lauraceae, Dioscoreaceae, Poaceae, Rosaceae and Myrtaceae. Genera with a higher number of species are Xanthosoma, Persea, Dioscorea, Prunus, Psidium, Phaseolus, Solanum, Vigna, Capsicum, Manihot, Theobroma, Ipomoea and Oryza. A total of 26 endemic species are found, which belong to genera Xanthosoma, Persea, Dioscorea, Prunus and Manihot. The primary gene pool of crops include native species from genera such as Manihot, Solanum (Section Petota), Lycopersicon, Ananas, Capsicum, Dioscorea, Xanthosoma, Phaseolus, Theobroma, Ipomoea, Gossypium, Arracacia and Psidium. Genera with native species weakly related to crops are Saccharum, Persea, Ipomoea, Prunus, Vigna, Solanum (Section Melongena) and Daucus. Crop genera without native species in Venezuela are Allium, Musa, Brassica, Spinacia, Helianthus, Pisum, Lactuca, Citrus, Elaeis, Beta, Glycine and Triticum. Only a few taxa have already been evaluated according to the IUCN criteria, and Venezuelan accessions of crop wild relatives in national and international genebanks are very scarce.  相似文献   

12.
Results from surveys of low-ANC lakes (high elevation, and seepage lakes), and of surface waters in dystrophic, acidic bogs, indicate that acidic precipitation and organic acidity are each generally necessary, but not solely sufficient, for chronically acidic status in Maine lakes. Acidic, low DOC (ANC < 0; DOC < 5 mg L-1) lakes of all hydrologic types are acidic due largely to acidic deposition; high DOC (DOC > 30 mg L-1) acidic seepage lakes are acidic due largely to organic acidity, and high DOC drainage lakes are acidic due to a combination of both factors. No low DOC drainage lakes are known with pH less than about 5.0, suggesting that organic acidity is necessary to depress lake pH values to below 5 in Maine at current deposition loadings,The dominant anion of low DOC, acidic waters is sulfate. Acidic waters with intermediate concentrations of DOC (5 to 30 mg L-1), may be dominated by S04 and/or organic acidity. Seepage-input lakes were the only group to include both organically-dominated (37% of the acidic lakes) and S04-dominated members (63% of the acidic lakes). High DOC systems are typically low pH bogs, and are all organic acid-dominated.  相似文献   

13.
新疆伊犁察南灌区土壤盐分特征   总被引：2，自引：0，他引：2  
以察南灌区土壤为研究对象,对不同含盐量土壤进行盐化程度分级,并对该地区土壤盐分特征进行相关分析和主成分分析,以及对土壤盐分因子区域影响因素进行探讨。结果表明:察南灌区以碱性土壤为主,HCO_3~–是影响该灌区土壤p H最强的因子;对灌区0~100 cm土体土壤的分析表明,灌区盐化土面积约为总灌溉面积的1/4,盐渍化风险较大;相关性分析显示,HCO–3、Cl~–、SO_4~(2-)、Ca~(2~+)、Mg~(2~+)、Na~+、K~+为盐分主要组成离子,总盐分与各离子之间均呈正相关关系,与总盐分相关性最强的阴离子为SO_4~(2-),相关性最强的阳离子为Mg~(2~+);主成分分析显示,HCO_3~–、Cl~–、K~+为影响该灌区土壤盐分特征的主导因子;通过盐分因子区域影响因素定性分析可知,除HCO_3~–和pH是由河流以及地下水综合作用影响外,其他盐分因子均主要受河流影响。  相似文献   

14.

Introduction  

Sequential fractionation procedures have been an important tool in the study of phosphorus (P) dynamics in soils and sediments for over 50 years. Throughout this period, the various methodologies have been thoroughly reviewed, and several limitations are widely acknowledged, but there are also aspects of P fractionation that have received little or no discussion. As there are few alternatives to fractionation procedures, in order to advance the usefulness of these techniques, we need to explore the undisclosed variables that may falsely bias our interpretation.  相似文献   

15.
上黄村土地类型有河滩、台坪、沟掌、梁和坡。土地类型对土壤养分变化的影响:有机质、全氮和水解氮是坡>阳坡>梁>台坪>沟掌>河滩>沟坡;磷钾是台坪、沟掌和河滩>台、阳坡、梁和沟坡。土地利用方式不同也影响土壤养分分布:（1）草地土壤养分变化是有机质、全氮和水解氮:为半阴半阳坡>阴坡>轮荒地>人工草地>农耕地,磷钾则相反,（2）台坪农地土壤养分呈放射状分布;（3）土壤微量元素的变化基本类似于磷钾。  相似文献   

16.
秋延迟番茄氮、磷、钾优化施肥方案研究   总被引：4，自引：2，他引：2  
采用三因子二次饱和D-最优设计(310),研究了氮、磷、钾配施对秋延迟番茄产量和品质的影响,并建立了以氮、磷、钾用量为变量因子,番茄产量和品质为目标函数的三元二次数学模型。通过对模型解析表明,氮、磷、钾对番茄产量和品质均有显著影响,且两两间存在显著的互作效应,但以钾肥对番茄产量、品质的影响较大。在低水平条件下,番茄产量、品质均随氮、磷、钾使用量的增加而提高;当氮、磷、钾用量过多,则导致产量、品质降低。通过计算机模拟运算得出,本试验条件下,番茄产量达140 t/hm2、品质综合评分达95分以上的施肥方案为N 520.2～758.4 kg/hm2、P2O5294.8～367.3 kg/hm2、K2O 1051.5～1299.8 kg/hm2,适宜的N、P2O5、K2O施用比例约为1∶0.52∶1.84。  相似文献   

17.
栽培密度和施肥水平对黄花蒿生长特性和青蒿素的影响   总被引：7，自引：0，他引：7  
采用大田试验,研究不同密度和施肥水平对黄花蒿生长、生物量分配和青蒿素含量的影响。试验设3个密度水平: 高密度（111111株/hm2）、中密度（55555株/hm2）和低密度（27778株/hm2）。 各密度设3个施肥水平(复合肥,N-P2O5-K2O为15-15-15): 不施肥、低肥（60 kg/hm2）和高肥（120 kg/hm2）。结果表明,黄花蒿对密度和养分条件变化的适应性较强,其中密度是植株大小、生物量分配和产量有关参数的主要决定因子,而青蒿素含量由施肥水平决定。相同施肥水平下,黄花蒿的基径与分枝数均随密度的降低而显著增大,其单株生物量也随密度的降低而显著增大; 中、高密度黄花蒿的支持结构生物量分数均显著大于低密度,低密度黄花蒿的根生物量分数和根/冠比显著大于中、高密度。相同密度下,施肥水平对黄花蒿的单株生物量影响不显著,但显著影响其生物量分配。低密度下,黄花蒿根生物量分数和根/冠比随施肥水平的增高而显著降低; 高密度下,黄花蒿叶生物量分数随施肥水平的增高而显著增大。所有处理中,低密度低施肥水平黄花蒿的青蒿素含量最高,中密度低施肥水平的叶产量和青蒿素产量最大。本试验条件下,黄花蒿栽培以密度55555株/hm2、 施肥60 kg/hm2为宜。  相似文献   

18.
Constructed wetlands for the treatment of organic pollutants   总被引：2，自引：1，他引：2  
Background  Constructed wetlands (wetland treatment systems) are wetlands designed to improve water quality. They use the same processes that occur in natural wetlands but have the flexibility of being constructed. As in natural wetlands vegetation, soil and hydrology are the major components. Different soil types and plant species are used in constructed wetlands. Regarding hydrology surface flow and subsurface flow constructed wetlands are the main types. Subsurface flow constructed wetlands are further subdivided into horizontal or vertical flow. Many constructed wetlands deal with domestic wastewater where BOD and COD (Biochemical and Chemical Oxygen Demand respectively) are used as a sum parameter for organic matter. However, also special organic compounds can be removed. Objective  The objectives are to summarise the state-of-the-art on constructed wetlands for treatment of specific organic compounds, to the present the lack of knowledge, and to derive future research needs. Methods  Case studies in combination with a literature review are used to summarise the available knowledge on removal processes for specific organic compounds. Results and Discussion  Case studies are presented for the treatment of wastewaters contaminated with aromatic organic compounds, and sulphonated anthraquinones, olive mill wastewater, landfill leachate, and groundwater contaminated with hydrocarbons, cyanides, chlorinated volatile organics, and explosives. In general the removal efficiency for organic contaminants is high in all presented studies. Conclusion  Constructed wetlands are an effective and low cost way to treat water polluted with organic compounds. There is a lack of knowledge on the detailed removal pathways for most of the contaminants. Removal rates as well as optimal plant species are substance-specific, and also typically not available. If a constructed wetland provides different environmental conditions and uses different plant species the treatment efficiency can be improved. Recommendations and Outlook  There is a great need to lighten the black box ‘constructed wetland’ to obtain performance data for both microbial activity and the contribution of the plants to the overall removal process. Also genetic modified plants should be considered to enhance the treatment performance of constructed wetlands for specific compounds.  相似文献   

19.
A model has been developed to estimate the regional emission of greenhouse gases from land-use related sources. Driving forces for this model are the changing regional demand for food and wood products driven by demographic and economic developments (Zuidema et al., 1994). To include the environmental conditions, which are essential factors determining the flux for certain sources, emissions are grid-based where possible. Grid-based explicit calculations are given for CH4 emission from rice, wetlands, emissions from deforestation, savanna burning and agricultural waste burning and N2O from natural soils, arable lands and deforestation. For a number of sources (landfills, domestic sewage treatment, termites, methane hydrates and aquatic sources) geographically explicit calculations are not yet possible because of data limitations. For most of the sources the global results of the calculations are in agreement with other scenario studies, although there are differences for a number of individual sources.  相似文献   

20.
内蒙古腰坝绿洲的土壤盐渍化特征   总被引：2，自引：0，他引：2  
[目的]研究内蒙古阿拉善左旗腰坝绿洲土壤盐渍化特征及土壤盐分离子分布规律,为研究区农业生产发展及生态环境保护计策提出合理依据。[方法]通过在野外考察、GPS定点、样品采集和处理并借助Excel和SPSS软件,运用统计学方法研究了该区土壤盐离子含量、总碱度与土壤离子含量之间的关系、土壤含盐量以及盐离子间的相关性。[结果]灌区土壤pH值平均值为8.13,为碱性土,土壤盐分含量较高,其中0—10cm土壤盐离子含量最高,平均值达到4.49%。阳离子主要是Ca2+和K++Na+,阴离子主要是SO2-4Cl-HCO-3,CO2-3含量微小。0—10cm土层和10—60cm土层中SO2-4与Ca2+均有极显著正相关,相关性均大于0.95,因子分析中SO2-4与Ca2+,Cl-和K++Na+发生"聚类"现象。[结论]灌区盐渍化土主要为硫酸盐渍土,其次为氯化盐渍土,该盐渍土危害植被生长。  相似文献   

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